Nontarnishing detergent compositions containing salts of antimony or bismuth



United States Patent 2,829,103. NONZIARNISEHNG DETERGENT COMPQSITIONS.

CONTAINING. SALTS. OF ANTIMONY 0R BIS- E'dgar E. Ruff, Bergenfield, and Elwin E. Smith, Paramus, N; J.', assignors,to.Levcr Brothers Company, New York, N." Y., a-corporationofMaine 1 No Drawing, Application June 28,1956

S'erialNo. 594,352.

1'42Cl2'iin1s. (Cl. 252--135) invention relates. to. detergent. compositions. con. tai'riingltarnishinhibitors and) more particularly. to. polyphospliate; compositions. containing, water-soluble.- inors ganicsaltsofantiinony or= bismuth. astarnishinhibitors;

Compositions containing polyphosphates are now widely used..for detergentand other. purposes. Aqueous solutions. of. polyphosphates tend whenat certain. pH values. to..- ta'rnisli, German. silver a. nickelszinc-copper alloy)" to.a variety of..."shades.from yellow. to bluishsblack, especially the. solutions are. at: elevated temperatures and. are. allowed to. remain. in 1 contact. with-the alloy, for several; minutes. Since German: silver is frequenfly used for household. articles commonly washed in.- polyphosphate-built detergentcompositions, it is evident. that this is a serious problem.

In accordance: withtthe instant.invention-polyphosphate compositions are: provided: containing a.- tarnishzinhibitor which compositions inhibit theaformatiomoftarnish upon German silver. The. tarnish inhibitors of the-invention are water-soluble. inorganic salts of. antimony or bismuth, for example, antimony trichloride, antimony pentachloride, antimony trifluoride, sodium meta-antimonite, bismuth bromide, bismuth trichloride,- bismuth sulfate, andbismuth nitrate.

An amount ofthe water-soluble inorganic saltnof' ans timony or. bismuthv is added to the polyphosphate comr position. whichis .suflicientto give tarnish: inhibitionwhen the composition is used in its normal way. It'will be understoodv thattheamount required will depend: impart upon the tarnish inhibiting properties of' the particular salt. ofantimony orz bismuth in question, upomthetendency of the polyphosphate with which it is used to: tarnish. German silver, and upon the amount of the polyphosphate. present. In general, therefore, at least about 0.7% ofthe water-solubleinorganic salt of antimony or bismuth based on the weight of the polyphosphate present in the detergentcomposition will inhibit theformation of tarnish by th'e'composition. The maximum amountof the: salt: of antimony orbismuth is not critical, but more than is necessary to give the desired effect will usually not be. used, and of course an amount in excess of that soluble inan aqueous solution of the composition would not.be. used.. In most cases, the maximum suggested would be about 15.0% based on the weight of polyphosphate.

The tarnish inhibitors of the present invention. are effective with water soluble alkali metal polyphosphates at ofpolyphosphate in-the compositions being dictated only by the. optional presence of organic nonsoap detergents and builders. which might be included in the detergent compositions.

Examples of such. additional optional components are organic nonsoap detergents .which may be either anionic, cationic, or nonionic detergents and builders, water, and inert materials. These detergent compositions may contain alkali metal polyphosphate in any'amount, usually between 20% and 50%; conventional proportions'of nonsoap detergent; usually within the. range between 5% and 40%; from about 0.7% to about 15.0% of a water,- solubleinorganic salt of antimony or bismuthbased. on the weight of the polyphosphate; andthe-balancebuilders and inert. materials.

The alkylaryl sulfonates are a class of anionic detergents which may be included in the detergentcompositions. One example thereof is the sulfonated phenyl polypropylene alkanes, characterized by the branched chain structure of polypropylene and a tertiary alkyl car- SOsM where M'is hydrogen, an alkali metal or an organic amine cation, and R and R are alkyl, of the type formula ChI-I and at least one R is a polypropylene group, the whole alkyl group containing preferably twelve to fifteen carbon atoms; These are known compounds whose preparation and properties are set forth in U. S. Patent No. 2,477,383 to Lewis, issued July 26, ,1949; they are available in commerce-under the trade names Oronite, Ultrawet, and Neolene.

Another class of useful nonsoap detergents are the amidoalkane sulfonates which are characterized by the following structure:

where A is hydrogen. or alkali metal, i. e., ammonium, sodium, or potassium, n is a small whole number from one to about five, preferably two or three, R is hydrogen, or an alkyl, aryl, or cycloaliphatic group, such as methyl, and R is an alkyl or alkylene radical, such as myristyl, palmityl, oleyl and stearyl. 'Sodium palmitic tauride, so dium palmitic methyl tauride, sodium myristic methyl tauride, sodiumpalmitic-stearic methyl tauride and sodium palmitic. methyl amidopropane sulfonate are typical examples thereof.

These-compounds are preparedby interactingthe corresponding;aliphatieacid. anhydride or halide with an, or

ganic; aliphatic aminosulfonic acid, such as, taur'ine,

NHgfifi CH sO Hg, and the various. N-substituted tau, lines, such as N-methyl taurine, or aminopropane. sulfonic acid, NH2(-CH- SO H.

Qtherywater-soluble alkyl aromatic sulfonicacids may constitute optional components, suchas those prepared by. alk-ylating benzene; or, naphthalene with a. kerosene fraction followed by sulfonation, to. aliphatic sulfonic:

acids, esters ofsulfuric acid with aliphatic alcohols of tento; eighteen carbonatoms, particularly those. derived.-

by the reduction; of coconut, oil, palm, oil. and likelong and sulfuric: acid; esters-of: monoglyceridesz and: glycerol monoethers: employed.

The. tarnish; inhibitors, are;v also. useful with nonionic.-

The saltsof these: acids are ordinarily-- detergents containing polyphosphates, such as, for example alkyl oxyether and ester and thioether and ester detergents having the following general formula: R--A-(CH CH O),-CH CH OH where R is a straight or branched chain saturated or unsaturated hydrocarbon group having from eight to eighteen carbon atoms or an aralkyl group having a straight or branched chain saturated or unsaturated hydrocarbon group of from eight to eighteen carbon atoms attached to the aryl nucleus, and attached to A through the aryl nucleus, A is selected from the group consisting of ethereal oxygen and sulfur, carboxylicester and thiocarboxylic ester groups and x is a number from eight to twenty. R can, for example, be a straightor branched chain octyl, nonyl, decyl, lauryl, myristyl, cetyl or stearyl group, or an alltyl aryl group such as octylbenzene, nonylbenzene, decylbenzene, stearylbenzene, etc.

The sulfated ethoxynated derivatives of the above also are useful anionic detergents:

where M is hydrogen or an alkali metal or organic amine cation and x, A and R are as above.

When R is alkyl it will be evident that the detergent can be regarded as derived from an alcohol, mercaptan, oxy or thio fatty acid of high molecular weight, by con densation with ethylene oxide. Typical of this type of alkyl ether are the condensation products of oleyl or dodecyl alcohol or mercaptan with from eight to seventeen moles of ethylene oxide, such as Emulfor ON, Nonic 218 and Sterox SE and SK. Typical alkyl esters are Gl226 and Renex" (polyoxyethylene ester of tall oil acids), Sterox CD and Neutronyx 330 and 331 (higher fatty, acid esters of polyethylene glycol).

Where R is aralkyl, the detergent can be derived from an alkyl phenol or thiophenol.

The ethoxynated alkyl phenols and thiophenols have the following general formula:

where R is a straight or branched chain saturated or unsaturated hydrocarbon group having at least eight carbon atoms up to approximately eighteen carbon atoms, A is oxygenor sulfur and x is a number from eight to twenty. R can, for example, be a straight or branched chain octyl, nonyl, decyl, lauryl, cetyl, myristyl, or stearyl group. Typical are the condensation products of octyl sodium and potassium silicates, and sodium and potassium carbonates. L

In addition to or instead of the above mentioned supplemental inorganic salts, organic materials such as sodium carboxymethyl cellulose can be used as builders.

The builder mixture is so chosen among alkaline, neutral, and acidic salts that the composition obtained in an aqueous 0.14% washingsolution has a pH of about 8 or above. Preferably its pH lies within the range of about 8 to about 11, and more preferably in the range of about 10 to about 11, since solutions which are more alkaline may be irritating to the skin and tend to weaken some fabrics, particularly woolens.

The detergent compositions of the invention inhibit the formation of tarnish upon German silver in either hard or soft water. compositions may exist in any dry form, such as drum- It will be appreciated that the detergent (ill 4 dried or spray-dried detergent compositions, or may be in liquid form.

The polyphosphate detergent compositions may be prepared by conventional methods, as by blending the ingredients thereof in an aqueous solution or slurry and then drying the resulting mixture in a spray or drum dryer at elevated temperatures. The tarnish inhibitor may be added to the polyphospsate composition in any stage of its manufacture, to the finished polyphosphate composition, or to the polyphosphate solution. The property possessed by salts of bismuth of forming highly soluble compounds with phosphates and other basic substances, imposes limitations upon the manner in which salts of bismuth may be incorporated into detergent mixtures. The salts of bismuth may not be added to a detergent slurry as customarily prepared for heat drying except as a clear acid solution, in which case the pH of the slurry must be adjusted to the desired level before drying. The salts of antimony, however, may be incorporated by adding the solid compound to the detergent slurry before drying.

The compositions of the invention will be further illustrated by the following examples wherein typical watersoluble inorganic salts of antimony or bismuth, namely sodium meta-antimonite and bismuth nitrate, were employed in the compositions. The salts of antimony were tested as a solution of sodium meta-antimonite, prepared by dissolving 0.5 gram of antimony trichloride in an aqueous solution of sodium hydroxide, and making up the volume to one liter. The salts of bismuth were tested as a solution prepared by dissolving 0.614gram of bismuth nitrate pentahydrate in somewhat less than one liter of water, adding hydrochloric acid until clear, and making up to a volume of one liter.

In these examples the following test procedure was employed. Five grams of a polyphosphate composition (or an equivalent weight of a component thereof where specified) were dissolved in 600 milliliters of water. Onetenth of this volume, or milliliters, was placed in a 200 milliliter beaker, and the required volume of inhibitor solution added. The volume of solution inthe beaker was made up to milliliters. The final concentration of polyphosphate composition or component is equivalent to five grams whole composition per quart of water. The pH at room temperature was adjusted to the desired level with sodium hydroxide or hydrochloric acid solutions. The solution was then heated to 1-165 F., and placed in a water bath to maintain the temperature of the solution at 160-165 F. A German silver metal strip, 1 inch by 6 inches, cleaned with a Noxon metal polish. rinsed, and buffed with a cloth, was partially immersed in the solution and allowed to remain for one-half hour. At the end of that time, the strip was removed, rinsed, dried with a cloth, and visually examined for tarnish. The effectiveness of the tarnish inhibitor was rated as follows:

Grade No. Degree of Tarnish 0 No tarnish. 1.- Interface stain only. 2 Barely noticeable tarnish. 3.. Slight tarnish. 4. Moderate tarnish.

Considerable (heavy) tarnish. Severe, as when inhibitor is absent.

EXAMPLES 1-12 To separate portions of the polyphosphates listed below dissolved in distilled water were added varying propor- Percent Antimony Salt (expressed as antimony trl-. chloride) (polyphosphatebasis) t Polyphosphate Tarnlsh Grade Tetrasodium Pyrophosphate (Examples 1-2) 6 2 Pentasodium Tripolyphosphate (Examples 3-.4) 6 v 2. Sodium Hexametaphosphatc (Examples 5-6). 6 2 Percent Bismuth Nitrate (pclyphosphate basis).... 0.0 0.7 6. 7

Polyphosphate Tarnish Grade Tetrasodium Pyrophosphate (Examples 7-9) 6 3 1 Pentasodlum Tripolyphosphate (Examples l0-l2) 6 3 1 The addition of a water-soluble inorganic salt of antimony or bismuth to polyphosphate compositions, containing an organic nonsoap detergent, which may be either anionic, nonionic, or cationic, as well as supplemental builders inhibits the formation of tarnish by such detergent compositions. This is clearly illustrated by the examples set forth below wherein the eight compositions of Table I were employed.

6 amples 18-20 the pH' of the test solution was 9, while in Examples;2 1 L-27 thepH' of thetest solution was 11.

Percent Sodium Meta-antimonite (expressed as antimony trichloride),

basis Grading (Composition A) (Examples 13-17) 1 6 polyphosphato N rate, polyphosphate basis Grading (Composition A) (Ex- I amples 21-2 Grading (Composition B) (Examples 24-27) 6 2 2 1 A water-soluble inorganic salt of antimony or bismuth is eiiective as a tarnish inhibitor in poiyphosphate compositions containing an organicn'onsoap detergent as well as supplemental builders when the alkali metal polyphosphate is other than tetrasodium pyrophosphate or pentasodium tripolyphosphate, for example, sodiumhexanietaphosphate or hexasodium tetrapolyphosphate. This is clearly illustrated by Examples 28-35 set forth below.

EXAMPLES 28-31 Fivegrams each of Compositions F and G per quart of distilled. water tested in accordance with the test procedure at pH 10 both tarnished German silver to a grading of 6, i. e., severe tarnish. When 6.7% of. sodium metaantimonite (expressed as antimony trichloride) based on the weight" of polyphosphate was added to Compositions F and G, the tarnish'grading of both compositions upon German silver at pH 10 was reduced to grade 1, indicating interface stain only.

Table l Compositions A B 0 D E i F G H Sodium Dodecylbenzeue Sulfonate 18.0 18.0 18.0 18.0 Sodium Pentadecylbenzene Sultonate. 18. 0'

Laurie Ester of N-(beta-hydroxyethyD- alpha-(chloropyridinlnm) acetamide [Emulsept] Pluronic L-64 Pentasodium Tripolyphosphate Tetrasodlum Pyrophosphate- Sodium Hexametaphosphate- Hexasodium Tetrapolyphosphate Sodium Silicate Sodium Carbonate In. Compositions A through H the amounts of the various components are: expressed in percent by weight. Pluronic L-64 is an organic nonionic nonsoap detergent havingthe empirical formula prepared by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol where b is an integer. selected. from the group consisting of 26 to 30 and a plus c is an integer such that the molecule contains from 40%. to of ethylene oxide.

Examples 13-27 show that a t least about 0.7% of a water-soluble inorganic salt of antimony or bismuth based on the weight of polyphosphate inhibits the formation of tarnish by polyphosphate compositions containing an organic anionic nonsoap detergent and supplemental build.- ers.

EXAMPLES 13-27 Tofivc grams each of Compositions A and Bthere was separately added sodium, meta-antimonite and bismuth nitrate in the, proportions, shown below and the. test procedure carried out with the foliowing results. In Examples 13-17 the pH of the test solution was 10. In Ex-- EXAMPLES 32-35 Five grams each of Compositions F and G per quart of distilled water tested in accordance with the test procedure at pH 10 and 11 respectively tarnished German EXAMPLES 3637 'Five grams of Composition H per quart of distilled water tested in accordance with thetest procedure at pH 10 tarnished German silver to a grading of 6, i. e., severe tarnish. When- 6.7% of sodium meta-antimonite {expressed as antimony trichloride) based on the weight'of, polyphosphatewasadded to Composition H, the tarnish grading of" the composition upon German silver at pH" 10 was reduced to grade 1, indicating'interface stain only.

7 Water-soluble inorganic salts of antimony or bismuth are also etfective as tarnish inhibitors in polyphosphate compositions containing either an organic cationic nonsoap detergent or an organic nonionic nonsoap detergent as well as supplemental builders, as illustrated by Examples 38-45.

EXAMPLES 38-41 EXAMPLES 42-45 Five grams each of Compositions C (cationic dctergent) and D (nonionic detergent) per quart of distilled water tested in accordance with the test procedure at pH 11 tarnished German silver to grade 6. When 6.7% of bismuth nitrate based on the weight of polyphosphate was added to each of these compositions, the two compositions so produced then had a tarnish grading at pH ll of 1, indicating interface stain only.

The amount of the alkali metal polyphosphate present in the polyphosphate compositions may be varied as noted above and as further illustrated by Examples 46-48 wherein only 15% of a polyphosphate was used in the detergent compositions.

EXAMPLES 46-48 Fifteen percent of pentasodium tripolyphosphate was employed in Composition B with the amount of sodium sulfate being increased to offset the decrease in the pentasodium tripolyphosphate content of the composition (30% additional sodium sulfate). Five grams of this modified composition per quart of distilled water at pH 10 had a tarnish grading of 4 upon German silver metal, whereas five grams of the modified composition per quart of distilled water which also contained 6.7% of sodium meta-antimonite (expressed as antimony trichloride) based on the weight of polyphosphate at pH 10 had a reduced tarnish grading of 1, while five grams of the modified composition per quart of distilled water which also contained 6.7% of bismuth nitrate based on the r weight of polyphosphate at pH 10 also had a reduced tarnish grading of 1.

The water-soluble inorganic salts of antimony and his muth are effective as tarnish inhibitors when incorporated in a detergent-polyphosphate slurry and the slurry drumdried as shown by Examples 49 and 50.

EXAMPLE 49 The composition shown below was prepared in the form of an aqueous slurrry having 30% water content and drum-dried. Five grams of'the drum-dried product per quart of distilled water tarnished German silver only to grade 1.

1 Percent antimony trichloride, based on poiyphosphate, 1.1.

,The composition. shown. below was prepared in the form. of an aqueous slurry having 30% water content and drum-dried. Five grams of the drum-dried product per quart of distilled water tarnished German silver only to grade 1.

Composition Percent by Weight Sodium Dodecylhenzene Sult'onate 18.0 Tetrasodiuln Pyrophosphate .r 45. 0 Sodium eilicate 6. 0 Sodium Carbonate 3.0 Sodium Garboxymethylceilulose 0. 5 \Vater 10.0 Sodium Sulfate... 17.0 Bismuth Nitrate I 0. 5

Total H 100.0

1 Percent bismuth nitrate, based on polypliosphutc, 1.1.

Examples 51-53 illustrate the fact that the watersoluble inorganic salts of antimony and bismuth are eifective as tarnish inhibitors in polyphosphate compositions when the polyphosphate compositions are used in hard water. It will be noted that in all of the previous examples the water was soft water,.i. e., distilled water.

EXAMPLES 51-53 Five grams of Composition B per quart of water having a hardness of 180 p. p. m. at pH 10 tarnished German silver to grade 5, whereas five grams of Composition B containing 6.7% of sodium meta-antimonite (expressed as antimony trichloride) based on the weight of polyphosphate per quart of water having a hardness of 180 p. p. m. at pH 10 tarnished German silver only to grade 1, while five grams of Composition B containing 6.7% of bismuth nitrate based on the weight of polyphosphate per quart of water having a hardness of 180 p. p. m. at pH 11 tarnished German silver only to grade 1. p The effectiveness of water-soluble inorganic salts of antimony and bismuth as tarnish inhibitors with liquid polyphosphate detergent compositions is clearly illustrated in Examples 54-61.

EXAMPLES 5 4-5 7 Four 11.25 gram portions of the following liquid detergent composition were dissolved separately in one quart of distilled water and sodium meta-antimonate added thereto at the concentrations indicated below. The tarnish grading of a strip of German silver metal inserted in each of the solutions at pH 9 is also set forth. It will be noted that 11.25 grams of the liquid product provides the same amount of polyphosphate (2.25 grams) as the standard five grams of granulated detergent containing 45% polyphosphate.

EXAMPLES 5 8-61 Four 11.25 gram portions of the liquid detergent composition set forth in Example 54 were dissolved separately in one quart of distilled water and bismuth nitrate added thereto at the concentrations indicated below. The tarnish grading of a strip of German silver metal inserted in each of the solutions at pH 11 is also set forth.

Example No 5s 59 E50 61 Percent Bismuth Nitrate, polyphosphate basis 0. 0. 7 1. 15. 0 Tarnish Grade 5 1 1 1 It should be borne in mind that this invention relates to tarnishing and tarnish inhibitors and does not pertain to alkaline corrosion and corrosion inhibitors. Tarnishing and corrosion of metals are two quite dissimilar phenomena. A discoloration is a principal manifestation of tarnishing, while a dissolving action characterizes corrosion of metal. Corrosion inhibitors are effective because they remove oxygen from the alkaline medium sur rounding the metal being corroded. The antitarnishing action of a water-soluble inorganic salt of antimony or bismuth on German silver, on the other hand, is due to a difierent mechanism,since the presence of oxygen is not necessary to the tarnishing action of polyphosphates on German silver.

Obviously many modifications and variations may be made in the invention herein set forth without departing from the spirit and scope thereof, and only such limitations should be imposed as are indicated in the appended claims.

We claim: I

l. A detergent composition consisting essentially of an alkali metal polyphosphate which in aqueous solution tarnishes German silver and a water-soluble inorganic salt of a metal selected from the group consisting of antimony and bismuth in an amount to lessen the tarnishing action of the polyphosphate.

2. A detergent composition consisting essentially of an alkali metal pyrophosphate which in aqueous solution tarnishes German silver and from about 0.7% to about 15.0% of a water-soluble inorganic salt of antimony based on the weight of polyphosphate to lessen the tarnishing action of the polyphosphate.

3. A detergent composition consisting essentially of an alkali metal polyphosphate selected from the. group con- 7 sisting of alkali metal tripolyphosphates and pyrophosphates which in aqueous solution tarnishes German silver and from about 0.7% to about 15.0% of a water-soluble inorganic salt of bismuth to lessen the tarnishingaction of the polyphosphate.

10 4. A detergent composition consisting essentially of from about 20% to about 50% of an alkali metal polyphosphate which in aqueous solution tarnishes German silver, from about 5% to about 40 of an organic nonsoap detergent, and a water-soluble inorganic salt of a metal selected from the group consisting of antimony and "bismuth in an amount from about 0.7% to about 15% based on the weight of the polyphosphate and suficient to inhibit such tarnishing.

5. A detergent composition as set forth in claim 4 wherein the polyphosphate is an alkali metal tripolyphosphate.

6. A detergent composition as set forth in claim 4 wherein the polyphosphate is an alkali metal pyrophosphate.

7. A detergent composition as set forth in claim 4 wherein the polyphosphate is an ankali metal hexametaphosphate.

8. A detergent composition as set forth in claim 4 wherein the polyphosphate is an alkali metal tetrapolyphosphate. I

9. A detergent composition as set forth in claim wherein the water-soluble inorganic salt is sodium metaantimonite.

10. A detergent composition as set forth in claim 4 'wherein the water-soluble inorganic salt is antimony trichloride.

11. A detergent composition as set forth in claim 4 1 References Cited in the file of this patent UNITED STATES PATENTS 2,303,399 Schwartz Dec. 1,1942

2,419,805 Wegst Apr. 29, 1947 2,425,907 Wegst Aug. 19, 1941 Schaeffer Nov. 18, 1952 

1. A DETERGENT COMPOSITION CONSISTING ESSENTIALLY OF AN ALKALI METAL POLYPHOSPHATE WHICH IN AQUEOUS SOLUTION TARNISHES GERMAN SILVER AND A WATER-SOLUBLE INORGANIC SALT OF A METAL SELECTED FROM THE GROUP CONSISTING OF ANTIMONY AND BISMUTH IN AN AMOUNT TO LESSEN THE TARNISHING ACTION OF THE POLYPHOSPHATE. 